Which of the following is an acceptable option for safety warning devices required for vehicles?

The correct answer is grounded in the regulations that specify the types of safety warning devices that must be carried in vehicles. The requirement is designed to ensure that drivers can adequately warn others of a hazard or breakdown that may occur on the road.

Option B presents three viable alternatives: three flares, three red electric lanterns, or three portable reflectors. Each of these devices serves the purpose of providing visibility and alerting other drivers to a potential danger. Flares and electric lanterns are particularly effective in low-light conditions, while portable reflectors can be used both day and night and are often designed to be highly visible.

This combination ensures flexibility for drivers, allowing them to choose the most appropriate method for their specific situation, which is crucial for maintaining safety on the road. Such options are standardized to create consistency in safety practices.

The other options don't meet the safety requirements as effectively. For instance, while two red flags or one reflector might seem useful, they may not provide adequate visibility compared to the full complement of three warning devices detailed in the correct answer. Similarly, tape markers or warning cones may not meet the necessary standards for visibility and warning effectiveness in all situations.